Hydraulic brake



- Feb.v 16, 1943. l M. L. MASTEL LER 2,310,975

HYDRAULIC BRAKE Filed Nov. 1, 1940 I' 2 v *INVENTOR I Patented Feb. 16, 1943 Malcolm L. Masteller, Miami, Fla.

Appiication November 1, 1940, Serial No. 363,903

(Cl. Sil-54.6)

2 Claims.

This invention relates to improvements in hydraulic braking apparatus and the object of the improvement is to provide means whereby the main body portions of a combined master cylinder and supply means can be turned from pipe stock, thereby enabling the elimination of the more expensive casting used in conventional master cylinders and eecting a material reduction in cost.

I attain this object by mechanism illustrated in the accompanying drawing which shows two types of combined master cylinder and supply means, both embracing the invention.

Referring to the drawing- Figure 1 is a vertical longitudinal section of a combined master cylinder and spring pressed piston reservoir.

Figure 2 is a vertical longitudinal section of a 'combined master cylinder and reservoir for liquid at atmospheric pressure.

Like numerals refer to like parts throughout the illustrations.

The device of Figure 1 comprises casing housing chamber I2, compressor piston I3 having an annular recess forming compartment I4 between said piston and said casing, with its primary -packing cup I5 and secondary packing cup I6, compression spring |1 urging said piston toward end washer I 8 which is held against a shoulder in said casing I I by retaining spring I9 which in turn is held in an annular recess in casing II by its own resilience, spring seat member 20, forward end closure member 2| with its gasket 22 and fitting 23 adapted for connecting conduit 24 leading to the brake; also a double acting checkvalve (seated on said end closure member 2| and held in place by said compression spring I1) including an inner check-valve made up of passage 25, valve member 2v6a-26b-2Ec, and compression spring 21, permitting a free outward ilow of liquid under pressure from chamber I2 and preventing its return through said passage 25, a heavier loaded outer check-valve made up of valve member 28 with its packing washer 29 seated on member 2|, and compression spring I1, permitting a restricted return flow of liquid under pressure to chamber I2; anda passage 30, more fully described and claimed in my co-pending application Serial 356,808 led September 14, 1940, now Patent No. 2,282,333, by-passin-g said check-valves; also actuating rod 3| which is conveniently attached to an operating crank and pedal not shown.

The above make up the master cylinder itself,

and surrounding it is the spring pressed piston reservoir, features of which are more fully described and claimed in Patent Number 2,188,913 dated February 6, 1940, said reservoir being designed to maintain the liquid supply under a predetermined normal pressure throughout the hydr-aulic system, to .be self .compensating in regard to the quantity of liquid stored therein and variations in its volume due to changes in temperature, and to deliver it to the high pressure lines as required.

It comprises casing 4|, head 42 which is spot-A welded to casing as at 42a, and has extended portions 42h to facilitate the mounting, packing cup 43 which is of the double ange variety, the outer flange engaging casing 4| and the inner flange engaging casing II, said members 42 and 43 constituting a liquid-tight closure for one end of the supply chamber, slidable annular piston 44 with its double ange packing cup 45, constituting a liquid-tight closure for the other end of said supply chamber, said piston having a length greater than its range, enabling it to .carry stop pins 46 of which there is a plurality disposed at intervals around the circumference of said piston, said pins travelling in slots as at 41 in the wall of said casing 4|, and serving also to indicate the position of said piston and in consequence the amount of available liquid contained in the reservoir; cover 48 attached to said casing 4| by means of pins 49 and their bayonetjoint slots 50, which are also disposed at intervals around the circumference of the device; washer 5| which gives a greater rigidity to said piston 44 and also serves as a spring seat; and a resilient means adapted to urge said annular piston inwardly and maintain the operating liquid under a predetermined normal pressure, usually about 6 to 8 pounds per square inch, including -compression springs 52 and 53 and piston-like member 54--55 which serves as a seat for said springs having a bearing on casing II for preventing weaving and buckling which would be inherent in a single spring of the required dimensions; bleeder ventI 56 with its plug 51, and filler port 58 with its check-valve tting 59 adapted `for engagement with a pressure filling device. The liquid in the reservoir is associated with that in compression chamber I2 by means of passages 60, 6| and 62 through casing I I, and passages 63 through the head of piston I3. Passages 6| and 62 in combination enable a circulation of the operating liquid through annular chamber I4 and facilitate the elimination of air therefrom.

In Figure 2 is shown a modified form of the invention adapted to a supply means in which the liquid is not kept at a greater than atmospheric pressure. The master cylinder itself is similar to that of Figure 1, excepting that it does not have passage 30, and surrounding it is the reservoir which comprises casing 8|, head 82 with its packing cup 83, piston-like head 84 with packing cup 85, said piston-like head serving 'as an end closure only and not being intended to slide as in the case of piston 44-45 of Figure l, retaining springs 86 and 8l held in annular grooves in casings Il and 8| respectively by their own resilience, compression spring 88 supporting said heads, with their packing cups, against their retaining springs 86 and 81, filler port 89 with plug 90 and its breather vent 9i. Head 82 may be pressed tightly on to casing Il or it may be slipped on and keyed as at 92 in order that it not be able to turn on casing Il. The device is mounted by means of U bolts 93.

What I claim is:

1. In a combined master cylinder and supply means wherein the supply means surrounds a portion of the master cylinder in such manner that the liquid supply forms an annular source around said master cylinder, the combination of a cylindrical casing, a closure for one end of said casing, a piston slidable Within said casing for creating pressure in a compression chamber forward of said piston, a recess in said piston forming an annular chamber between said piston and said casing, `a second tubular casing longitudinally surrounding a portion of said rst casing and annular end closures for said second casing each including a flexible rannular double anged cup, all forming an annular supply chamber ybetween said casings, and a plurality of passages associating said chambers with each other, substantially as described.

2. The combined master cylinder and supply means of claim 1 in which one of said annular end closures is an annular piston sldable in said annular supply chamber, associated with resilient means adapted to urge said annular piston inwardly and maintain the operating liquid under a -predetermined norm-al pressure, substantially as described.

MALCOLM L. MASTELLER. 

